Pacific Interlock demonstrated their porous paving stones. It was enlightening to watch them pour a glass of water directly on top of the paver and it soaked right through. I had been under the assumption that porous pavers meant pavers with holes for water to drain and plants to grow through. These look like conventional bricks, just have tiny pores to drain the water.

There were also many representatives of grey water and black water treatment systems. I think you get pay back pretty quickly on a large building or development if you can recycle some of your water. These systems are still too expensive for the average single family home owner.

In a place like the bay area, where rainfall is concentrated seasonally, storage often does not make sense. It is more practical to use rain water in wintertime for wash or toilets, and to reuse shower and sink water for toilets and irrigation during summer. Expensive filtration is required by code for any reuse of rainwater or grey water for plumbing purposes. It is now permitted in many jurisdictions to use grey water (only from laundry and bathroom sinks and showers,) for irrigation without filtration.

Nada… ends up being expensive and an administrative hassle, so is still rarely done as far as I know (hasn’t happened on any of my multifamily projects to date; though it might be different outside CA?) It’s an issue with billing; a 3rd-party agency handles billing, and it seems most props. just don’t want to deal with it unless they have to. This company claims that water submetering is now req’d in San Diego for new MF properties: http://www.multifamilyutility.com/about-news.html

One of my clients is looking at designing his future projects to be “submeter-ready”–ie plumb so that individual units can easily be submetered in the future. Just like “solar-ready”. What a great idea!